Revert of Delete "shutdown without closing browsers" path

chrome/browser/ui/ash/chrome_shell_delegate.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_UI_ASH_CHROME_SHELL_DELEGATE_H_
 #define CHROME_BROWSER_UI_ASH_CHROME_SHELL_DELEGATE_H_
 
 #include <string>
 
 #include "ash/shelf/shelf_item_types.h"
@@ skipping 33 matching lines @@
   virtual ~ChromeShellDelegate();
 
   static ChromeShellDelegate* instance() { return instance_; }
 
   // ash::ShellDelegate overrides;
   virtual bool IsFirstRunAfterBoot() const OVERRIDE;
   virtual bool IsMultiProfilesEnabled() const OVERRIDE;
   virtual bool IsIncognitoAllowed() const OVERRIDE;
   virtual bool IsRunningInForcedAppMode() const OVERRIDE;
   virtual void PreInit() OVERRIDE;
-  virtual void PreShutdown() OVERRIDE;
+  virtual void Shutdown() OVERRIDE;
   virtual void Exit() OVERRIDE;
   virtual keyboard::KeyboardControllerProxy*
       CreateKeyboardControllerProxy() OVERRIDE;
   virtual content::BrowserContext* GetActiveBrowserContext() OVERRIDE;
   virtual app_list::AppListViewDelegate* CreateAppListViewDelegate() OVERRIDE;
   virtual ash::ShelfDelegate* CreateShelfDelegate(
       ash::ShelfModel* model) OVERRIDE;
   virtual ash::SystemTrayDelegate* CreateSystemTrayDelegate() OVERRIDE;
   virtual ash::UserWallpaperDelegate* CreateUserWallpaperDelegate() OVERRIDE;
   virtual ash::SessionStateDelegate* CreateSessionStateDelegate() OVERRIDE;
@@ skipping 24 matching lines @@
 
 #if defined(OS_CHROMEOS)
   scoped_ptr<chromeos::DisplayConfigurationObserver>
       display_configuration_observer_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(ChromeShellDelegate);
 };
 
 #endif  // CHROME_BROWSER_UI_ASH_CHROME_SHELL_DELEGATE_H_